Co-extruded materials and methods

ABSTRACT

Co-extruded materials and methods for forming co-extruded materials that include images are disclosed. The method may include co-extruding two materials together to form a co-extruded workpiece. The first material may be a base material and the second material may be a graphic material used to form one or more images in a cross-section of the workpiece. One or more cross sectional parts that include the one or more images may then be generated by cutting, slicing or otherwise forming cross-sectional parts from the workpiece.

CROSS-REFERENCE TO RELATED APPLICATIONS

This Application is a Non-Provisional of Provisional (35 USC 119(e)) application 61/025,531, filed on Feb. 1, 2008.

TECHNICAL FIELD

This disclosure generally relates to co-extruded materials. In particular, this disclosure relates to co-extruded materials in which images are co-extruded with a device part.

BACKGROUND

As used herein, the word “image” refers broadly to any visual form, representation or depiction. An image may mean and include a logo, an icon, or any other graphic representation (i.e., words, numbers, letters, figures, etc.).

Many consumer products have one or parts in which one or more images are associated with the part. For example, consumer products generally referred to as “media players” may include a user input device (which may be in the form of a wheel, a knob, a button, etc.). The input device may provide images in the form of icons associated with recording and playback functions of the media player. The icons may include icons representing media player functions such as “pause,” “play,” “stop,” “fast forward,” “reverse,” etc.

Currently, there are several known techniques for attaching such icons or other images to the input device of a media player or other product parts. For example, the image may be printed on the product part after the part is formed. In this instance, the image may be stamped or printed directly on the front surface of the part (where “front surface” refers to a surface of the part intended to face the user of the device). Alternatively, if the part is sufficiently thin and/or sufficiently clear, the image may be printed on the back surface of the part. Printing the image on the back surface may improve durability to the image, as it is less prone to wear such as being rubbed off during use.

An alternative to printing the image directly on the product is to apply the image to the surface of the part in the form of a label or a film. Yet another technique for applying images to parts is using a technique known as twin-shot or double-shot plastic molding. Double-shot molding is a successive molding process in which the part is first injection molded. This part is then transferred to a second mold, where the image is injection molded against the part previously formed part.

BRIEF SUMMARY

This disclosure relates to co-extruded materials that include images and methods for forming co-extruded materials that include images. It addresses several issues that are typically encountered when including images on component parts.

A method for making a co-extruded part that includes one or more images may include co-extruding two materials together to form a co-extruded workpiece. The first material may be a base material and the second material may be a graphic material used to form one or more images in a cross-section of the workpiece. One or more cross sectional parts that include the one or more images may then be generated by cutting, slicing or otherwise forming cross-sectional parts from the workpiece. For example, the workpiece may be substantially cylindrical and cross sections may be generated from the workpiece to form one or more substantially circular parts. The workpiece may be extruded through a single die that includes a plurality of orifices that may be fed by one or more extruders.

The images may form, for example, a logo, an icon, or other graphic representations including text characters. A variety of materials may be co-extruded including ceramic materials, plastic materials or metallic materials. The co-extruded part may have any number of topographies, including, planar, convex, concave, or other complex topographies.

The co-extruded part may go through one or more additional processing steps prior to use. These additional processing steps may include shaping the part, grinding the part, and/or tumbling the part to remove burrs or micro-cracking.

A variety of component parts may be formed by the described co-extrusion processes. The component parts may, for example, be an input device part for a media player, an input device part for a phone.

BRIEF DESCRIPTION OF THE DRAWINGS

FIG. 1 illustrates an example of a co-extrusion process in which an input device is formed with an image formed throughout the cross section in accordance with some embodiments.

FIG. 2 shows an example of a dome shaped embodiment of an input part for a media player.

FIG. 3 shows a flow diagram that illustrates an example of a co-extrusion process for forming an input platform in accordance with some embodiments.

DETAILED DESCRIPTION

Described are co-extruded materials and methods for forming co-extruded materials. The described methods are useful in forming parts having associated images. The images are formed simultaneously and as an element of the part itself.

More specifically, the images thus formed may be more durable than images formed from conventional printing techniques, which may be rubbed off when exposed to physical wear since the images are formed only on a surface of the part. Further, unlike images applied to parts in label or film form, the images may be exposed to physical wear without the worry that the image will peel off or otherwise separate from the part. Additionally, the images may be formed using a range of materials, including materials that cannot be used in double-shot molding techniques, for example ceramics.

Further, the co-extrusion methods eliminate the requirement of forming icons on each input device separately and individually, one-by-one. Instead, a base extrusion material and one or more image co-extrusion materials are provided. The base extrusion material and the co-extrusion materials may be co-extruded through a die. Cross-sectional parts may be removed from the extrusion by cutting, slicing or other techniques (somewhat similar to slicing a loaf of bread into individual slices). Each of these thinner cross-sectional parts contains both the base co-extrusion material and image co-extrusion materials.

In an extrusion process, a continuous workpiece may be produced by forcing molten or hot material through a shaped orifice, i.e., the extrusion process may produce a length of a particular cross-sectional shape. The cross-sectional shape of the workpiece may be controlled at least in part by the shaped orifice. As the shaped workpiece exits the orifice, it may be cooled and thereafter cut to a desired length forming a product part. This process may be used to continuously produce parts with a desired cross sectional shape profile.

In a co-extrusion process, two or more materials may be extruded through a single die that has multiple orifices. The multiple orifices may be configured so that the longitudinally extruded materials merge and weld together during the extrusion process. In some embodiments, the various materials may be fed to the die from separate extruders, which may be configured to supply material to a single or multiple orifices. The co-extrusion process may be widely varied. The design of the extrusion die and orifices may be useful in ensuring that homogenous densities are produced with the various materials.

In one embodiment, a co-extrusion die may include a main orifice that defines the outer shape of a continuous length of workpiece and one or more inner orifices positioned within the main orifice that define various images within the continuous length or workpiece. In one example, a first extruder may supply material to the main orifice and a second extruder may supply material to the one or more inner orifices. Alternatively, in cases where there are multiple inner orifices, different extruders may supply similar or different materials to different corresponding inner orifices. In one example, each inner orifice may define a unique image within the overall extruded product formed from the main orifice.

The images may, for example, correspond to logos, icons or other graphic representations, including words, numbers, letters, and/or figures.

The base material and the images may have at least one different attribute so that the designs may be differentiated from the remaining portions of the workpiece. The attribute may, for example, be color or texture. For example, one material may be black while the other may be white.

The co-extrusion process may allow for a variety of materials to be used. In some embodiments the materials being extruded together may be similar. The materials, for example, may differ only in color or may include one or more of the same base ingredients. In other embodiments the materials being extruded together may be dissimilar.

A wide variety of materials may be co-extruded. These materials may include, for example, metals, metal alloys, plastics, ceramics and/or the like. By way of example, the metals may correspond to aluminum, titanium, steel, copper, etc., the plastic materials may correspond to polycarbonate, ABS, nylon, etc, and the ceramic materials may correspond to alumina, zirconia, etc.

In many embodiments the materials being extruded are preferably compatible. In one example, materials with relatively similar melt viscosities may be selected to help ensure a proper flow of material (e.g., laminar). The materials may have a melt viscosity within a factor of 5 at typical shear rates. In addition, the materials may be processable at the same temperature.

The location and/or dimensions of the orifices may impact the optimal degree of viscosity difference. In one example, the product part may be formed from compatible materials that allow capacitive sensing or other related sensing to occur there through. In one example, the workpiece may be formed from compatible ceramic materials (e.g., zirconia).

In one embodiment, the co-extrusion technique may be used to create a surface with ornamentation. In this embodiment, the extrusion may be cut across the longitudinal axis to form thin sections. The face of the thin sections may include the image ornamentation created by the co-extrusion. The surface may, for example, be applied to an input platform of an input mechanism. In one example, the co-extrusion may include at least a base material that corresponds to a main orifice and a graphic material that corresponds to multiple discrete inner orifices located within the main orifice. The base material may be formed into the intended outer shape of the input platform while the image material (which may be disposed within the outer periphery of the base material) may be formed into a variety of shapes including, for example, text and objects.

Any number of discrete shapes may be formed. In an example of an input platform for a media player, shapes that correspond to command identifiers such as menu, forward, back, play/pause may be formed. Forward and back may be formed as one or more triangles, and play/pause may be formed as a triangle with side-by-side bars. Alternatively, the command identifiers may be associated with a phone such as numbers 1, 2, 3, 4, 5, 6, 7, 8, 9, 0, *, #, etc. In addition or alternatively one or more of these identifiers may be formed as text.

Several advantages may be associated with these co-extrusion techniques. For example, different types or shapes of cross-sectional parts may be cut or sliced from the same base material, providing essentially identical graphics on each part. If each cross-sectional part is sliced from the same extrusion, each cross-sectional part may exhibit the same graphics irrespective of topography. For example, some or all of the cross-sectional parts might be substantially dome-shaped, substantially flat, or may have a variety of other topographies. In addition, these techniques enable the manufacture of multiple, substantially identical parts relatively easily and efficiently.

FIG. 1 illustrates an example of a co-extrusion process in which an input device is formed with an image formed throughout the cross section of the part. In this example, the images provide icons representative of functions associated with a media player.

In the example shown in FIG. 1, the base co-extrusion material 102 may be black zirconia ceramic and the graphic co-extrusion material 104 may be white zirconia ceramic. In the illustrated example, the black zirconia ceramic and white zirconia ceramic are co-extruded and then sliced to form multiple cross-sectional parts 108, with each of the pieces 108 being suitable for use as an input device for a media player.

In the example shown in FIG. 1 the “loaf” 106 of extruded material may be substantially cylindrical, and the individual cross-sectional slices 108 may be circular, although the loaf 106 may have any cross-sectional topography. In the illustrated example, the cross-sectional slices 106 may be of substantially equal thickness, although cross-sectional slices of varying thicknesses may also be obtained.

Techniques described herein may be used to provide images on products with topographies that would otherwise be difficult. For example, it may be difficult to print images on a dome or other three dimensional shape using prior art printing techniques. In contrast, the techniques described herein enable images to be provided on any surface, irrespective of topography.

FIG. 2 shows an example of a dome shaped input part for a media player. In the example shown in FIG. 2, one surface 202 may be substantially flat and opposing surface 204 may be substantially dome shaped. The dome shape may be formed by cutting the domes directly from the extruded workpiece. Alternatively, the dome shape may be formed after straight slices have been taken from the workpiece.

FIG. 3 illustrates an example of a simplified co-extrusion process 300 for forming an input platform in accordance with an embodiment of the techniques described herein. In the illustrated example the process begins at block 302 where a co-extrusion process may be performed along a longitudinal axis to form a continuous length work piece. The co-extrusion process may be configured to push or draw multiple materials through a die to create a continuous length workpiece with internal shaped images (e.g., via shaped orifices).

Thereafter, at block 304, the extruded workpiece may be cut along its continuous length into one or more sections. The face of one or more sections may include the shaped graphics. The face may, for example, be used as an input platform with unique and discrete command identifiers (the face being the portion that may be viewed and interacted with by the user). The input platform may, for example, correspond to the input face of the click wheel manufactured by Apple Inc, of Cupertino, Calif.

Additional processing steps may be used to further modify the face(s) of the segmented sections at 306. For example, one or more grinding operations may be performed. Grinding may include the process of removing material via abrasion as, for example, from materials too hard to be machined. Grinding may be performed to achieve several effects, including for example: (1) shaping the sections, and/or (2) obtaining a high degree of dimensional accuracy and/or surface finish.

The grinding process may include a rough grind that may remove a majority of material and create a flat part and then a fine grind to create the final shape. The grinding operations may also be used to cut holes and features into the enclosure as, for example, cutting openings in the front face of the enclosure. A CNC machine may be used to perform some or all of the grinding operations. Alternatively, the openings and features may be made with laser cutting, jet cutting or ultrasonic cutting means, for example.

In some cases, lapping operations may be performed to achieve extreme dimensional accuracy and superior surface finishes. In one implementation, the top and bottom faces may be first lapped to a tight tolerance and then the edges may be lapped thereafter. Additionally or alternatively, the parts may be machined, shaped, formed, forged and/or bent into other shapes.

The co-extruded parts may be tumbled to remove burrs from edges of the parts as well as to remove micro-cracking from the grinding process. For example, multiple parts may be thrown in a tumbler bin, which may be rotated for several hours.

The co-extruded parts may be cleaned and inspected before use. The inspection may include micro-photography as well as chemical composition analysis. When approved, the parts may be used to assemble the final product. In some cases, the process may include an additional step of applying a protective coating or protective features to the outside of the part. The coatings or features may for example be formed from deformable materials including silicon, foam or rubber materials. The coatings and protective features may be placed almost anywhere on the part, but in many cases they may be preferably are placed at least at the edges where the part may be susceptible to cracking.

One skilled in the relevant art will recognize that many possible modifications and combinations of the disclosed embodiments may be used, while still employing the same basic underlying mechanisms and methodologies. The foregoing description, for purposes of explanation, has been written with references to specific embodiments. However, the illustrative discussions above are not intended to be exhaustive or to limit the disclosure to the precise forms disclosed. Many modifications and variations are possible in view of the above teachings. The embodiments were chosen and described to explain the principles of the disclosure and their practical applications, and to enable others skilled in the art to best utilize the disclosure and various embodiments with various modifications as suited to the particular use contemplated. 

What is claimed is:
 1. A method of manufacturing a user input device for an electronic device, the user input device having a symbol embedded within a surrounding material, the method comprising: simultaneously extruding a first ceramic material through a main opening of a die and a second ceramic material through an inner opening of the die, the main opening and inner opening arranged so that the first and second ceramic materials merge and fuse together during the extruding forming an elongated workpiece, wherein the main opening defines an outer shape of the elongated workpiece and the inner opening defines an outer shape of the symbol; and forming the user input device by cutting a cross-sectional slice from the elongated workpiece, the cross-sectional slice having the first ceramic material and the second ceramic material, wherein the first ceramic material corresponds to the surrounding material and the second ceramic material corresponds to the symbol of the user input device.
 2. The method of claim 1, further comprising: feeding the first ceramic material to the main opening of the die from a first extruder and feeding the second ceramic material to the inner opening of the die from a second extruder.
 3. The method of claim 2, further comprising: shaping the cross-sectional slice to have a substantially flat surface and opposing substantially dome-shaped surface.
 4. The method of claim 1, wherein the symbol comprises at least one logo, icon, or graphic representation.
 5. The method of claim 1, wherein the symbol comprises at least one text character.
 6. The method of claim 1, wherein at least one of the first ceramic material and the ceramic second material comprise a zirconia ceramic material.
 7. The method of claim 1, wherein a shape of the main opening is different than a shape of the inner opening.
 8. The method of claim 1, further comprising grinding the cross-sectional slice.
 9. The method of claim 1, further comprising tumbling the cross-sectional slice removing burrs or micro-cracking.
 10. The method of claim 1, wherein the die includes multiple inner openings, wherein at least two of the inner openings have different shapes.
 11. The method of claim 1, wherein forming a cross-sectional slice comprises cutting a dome-shaped surface on the cross-sectional slice.
 12. The method of claim 1, further comprising configuring the cross-sectional slice for use as a visible element of an input device associated with a media player.
 13. The method of claim 1, further comprising configuration the cross-sectional slice for use as a visible element of an input device associated with a phone.
 14. The method of claim 1, wherein the user input device comprises two or more symbols, wherein each symbol corresponds to an inner opening of the die.
 15. The method of claim 1, wherein the elongated workpiece has a substantially cylindrical shape and the cross-sectional slice has a substantially circular shape.
 16. A method of manufacturing a user input device for an electronic device, the user input device having a figure embedded within a surrounding material, the method comprising: concurrently extruding a first ceramic material and a second ceramic material through a common die, the first ceramic material extruded through a first opening of the die and the second ceramic material extruded through a second opening of the die; forming a cylindrical workpiece by allowing the first ceramic material and second ceramic material to fuse together during the extruding, wherein the first opening defines an outer shape of the cylindrical workpiece and the second opening defines an outer shape of the figure; and forming the user input device by cutting orthogonal to a longitudinal axis of the cylindrical workpiece forming a cross-sectional slice having the first ceramic material and the second ceramic material, wherein the first ceramic material corresponds to the surrounding material and the second ceramic material corresponds to the figure of the user input device.
 17. The method of claim 16, further comprising: feeding the first ceramic material through the first opening via a first extruder, and feeding the second ceramic material through the second opening via a second extruder.
 18. The method of claim 16, wherein the first ceramic material has a different color than the second ceramic material.
 19. The method of claim 16, wherein the figure has a shape of at least one logo, icon, or graphic representation.
 20. The method of claim 16, wherein the die includes multiple second openings. 